Apparatus for surface grinding generally spherical elements



Jan. 31, 1967 H. H. GARDNER 3,300,905

APPARATUS FOR SURFACE GRINDING GENERALLY SPHERICAL ELEMENTS Filed Sept. 27, 1963 s Sheets-Sheet 1 FIG.

Jan. 31, 1967 H. H. GARDNER 3,300,905

APPARATUS FOR SURFACE GRINDING GENERALLY SPHERICAL ELEMENTS Filedsept. 27, 1963 3 Sheets-Sheet 2 j 59 72 63 6| ll 62 l -I-|O Jan. 31, 1967 H. H. GARDNER 3,300,905

APPARATUS FOR SURFACE GRINDING GENERALLY SPHERICAL ELEMENTS Filed Sept. 27, 1963 3 Sheets-Sheet 5 United States Patent 3,300,905 APPARATUS FOR SURFACE GRINDING GENERALLY SPHERICAL ELEMENTS Henry H. Gardner, Baton Rouge, La., assignor to Ethyl Corporation, New York, N.Y., a corporation of Virginia Filed Sept. 27, 1963, Ser. No. 312,241 2 Claims. (CI. 5133) This invention relates to apparatus for surface grinding generally spherical elements. More particularly, the invention relates to new and improved apparatus for surface finishing generally spherical elements of which the spherical plug elements of ball valves are typical.

Of recent years, spherical ball valves have achieved particular prominence in the process industries as replacements for more expensive and less satisfactory valve means such as tapered plug valves, gate valves, and the like. The attainment of widespread use of such valves has been in part a result of improvement in materials of construction thereof, viz., that is with respect to the metals of the balls employed, and also with the availability of certain polymeric materials from which are made the sealing rings engaging the spherical elements.

In the large sizes, valves of the above described type are quite expensive, the ball plug elements themselves being the most expensive component. Hence, in various classes of service in which the ball elements suffer mechanical abrasion or attrition, the maintenance and replacement of worn ball plugs is an expensive proposition.

The object of the present invention is to provide new and novel apparatus for resurfacing the spherical contour of generally spherical elements having a port completely therethrough on an axis thereof. More particularly, a specific object of the invention is to provide apparatus whereby gall marks, mechanical scarring or scuffing blemishes suffered during service can be removed in a highly eflicient manner and a truly spherical surface reestablished.

The details of the invention, and of a particular embodiment thereof will be understood clearly from the accompanying figures, wherein:

FIG. 1 is a front elevation view,

FIG. 2 is a side elevation,

FIG. 3 is a rear elevation view of a segment or subassembly of the apparatus,

FIG. 4 is an isometric view of the same sub-assembly shown in FIG. 3, and

FIG. 5 is a further enlarged illustration of an additional sub-assembly of the apparatus.

Referring to FIG. 1, and to FIG. 2 as necessary, the apparatus is supported on a base plate or table member 10, and the principal components include means for supporting the work piece 20 and for rotating thereof, and means for oscillating a grinding member on an arcuate path sweeping past the spherical portion of the work piece, and including means for slidably moving the grinding member toward the center of the work piece upon the completion of each stroke.

The work piece, as heretofore described, is a part spherical shape, being usually the ball of a balled valve, having a cylindrical port therein, and an aperture 21, being a rectangular or square hole in the surface whereby a valve stem can engage and twist the ball in its normal functioning in a ball valve.

Two standards 11 11 are provided for supporting an axle 12, upon which is mounted an expandible mandrel, including an expansible section 13, and conical nut members 14 14 By rotation of the nut members 14 14 toward the center of the work piece, the expandible 3,300,905 Patented Jan. 31, 1967 'ice section members are uniformly expanded and center the work piece 20 axially on the axle 12. Lateral positioning can be achieved by inspection, but a latching registration means or gauge 22 can be provided. By engagement of this member with the aperture 2-1, lateral registration of the Work piece 20 in a uniform manner is secured.

The axle '12 is an extension of or coupled to the axle of a gear reducer 17, driven by motor 18, the gear reducer- .motor set being mounted on a sub-base 19 for appropriate positioning. A pulley 16 also mounted on the axle 12 rotates and drives, by V-belt 23, the drive pulley of a speed reducer 25, having an output shaft 26 at right angles to the input shaft mounting the pulley 24.

A second mounting assembly or standard 31 is provided for the portion of the apparatus including the grinding means for surfacing the ball. The standard 31 has affixed thereto a fixed plate 32, upon which is pivotally mounted an additional plate member 33 having an arm extension 33 The orientation of the standard 31 and the fixed and oscillating plates. 32, 33, will be more fully understood from FIG. 2, and from FIGS. 3 and 4.

Referring to FIG. 4, the general orientation of the standard 31 and the several plates referred to will be readily seen. The fixed plate 32 is provided with a plurality of cam members 36 36 which actuate, as hereafter described, mechanism for traverse lgranding means to take successive cuts along its arcuate path. The oscillating plate member 33, in this embodiment, is also provided with two cam members 37 37 for actuating a switch means 38, for initiating and controlling operation of supplemental locking means as hereafter described.

Referring again to FIG. 1 and to FIG. 2, slidably mounted on the extension arm 33 of the oscillating plate 33 is a support plate 51, having an extension platform member 52 fixedly attached to and extending therefrom in the direction of the'workpiece 20. Mounted on the platform is a grinder drive motor 53, driving a pulley 54, which in turn drives, by a V-belt 55, a second pulley 56, on a shaft 57 which also mounts a grinding wheel 58. The position of the platform 52 on the extension arm 33 is established by a bolt member 59, attached to the platform, a spring member 60 being provided to depress the platform and slidable plate assembly 51, 52, against the action of the bolt member. The bolt engages a nut member 61, having a toothed periphery 62, as well as a segment 63.

The interrelation of the bolt member and nut member is illustrated more specifically by FIG 5. The nut member 61 engages and rests on a bracket 64 at the uppermost terminus of the extension arm 33 and retaining members 65 65 aflixed to the bracket 64 secure the nut member 61 in vertical position.

The slidable positioning of the plate 51 against the arm extension 33 is provided by slide ways 66 66 engaging and retaining the slide plate 51.

The additional segments of the operative mechanism associated with the plate extension 33 already mentioned with respect to FIG. 5, is further illustrated by FIG. 3, being a rear view elevation including the extension arm 33 Mounted on the arm 33 is a slidable member 67 retained in place by two guide members 68 68 and having mounted at its lower end a separate roller 69 which engages the circular surface of the fixed plate 32. It will be seen that as the plate 33, and the extension arm thereof 33 oscillates through an arc of approximately that engagement of the roller 69 with the cam members 36 36 will cause movement of the slidable member 67 along the extension arm 33 The terminus of the slidable member 67 engages a crank arm 73 pivotally attached to the extension arm 33 and retained by a spring 70 in yieldable engagement with the terminus of the slidable member 67. A slidable angle 71 is mounted on the upper extremity of the extension arm and has attached thereto a pawl 72 which engages the toothed periphery 62 of the nut member 61. The pawl 72 is yieldably pressed against the toothed periphery 62 by spring means, not shown. Thus, as the crank arm 73 is oscillated by the cam action already described, at each terminus of an oscillating arc, the pawl 72 causes minute rotation of the nut member 61. The nut 61 thus causes movement of the bolt member 59, which determines the position of the support plate 51 for the grinding mechanism.

As previously mentioned, supplemental locking means are provided in this embodiment to retain positioning of the grinding wheel 58 during an arc movement of the plate 33 and associated apparatus. Said supplemental mechanism includes an air cylinder 81 supported from the oscillating plate 33 through a slot 56 in the plate 51. The piston rod 82 of the air cylinder mechanism is capable of pressing a washer 83 against the surface of the plate 51 when air pressure is applied in the air cylinder 81. Air pressure is applied through a hosing, not shown, control being effected by means of a valve, not shown, whose action is initiated by the switch means 38. Such pressure locks together the support plate 51 to the oscillating plate 33. In actuation, the cams 37 37 mounted on the periphery of the oscillating plate 33, engage the limit switch mechanism 38 at positions associated with the arcuate positions of the cams 36 36 which actuate as already described the movement mechanism for adjust ing the position of the grinding means. The arcuate position of said cams is such that after the grinding mechanism has been moved in the manner already described, the air cylinder 81 applies pressure to the slidable plate 51 and rigidly afiixes its lateral position on the extension arm 33 To describe fully the overall functioning of theapparatus above described, the following describes the full sequence of operations.

A work piece 29 is mounted on the shaft, this requiring removal of one of the support brackets 11 sliding the work piece 20 in position and laterally adjusting it by gauge means 22, if desired, and tightening the nut members 14 14 to axially position the work piece. The support member or bracket 11 is returned and fastened in position.

The position of the grinding element is adjusted to the extremity at which only limited contact will be made with the irregular portions of the rough work piece, this being accomplished by manually retracting the grinding element. This is done by disengaging the pawl member 72 and retracting the bolt member 59 to the appropriate position by turning the nut member 61. The pawl is then allowed to engage the toothed periphery 62, the motor 18 is started and through the action of the drive devices already described, the work piece 20 is rotated, the oscillating plate is oscillated and the grinding element is rotated. It is preferable to have the work piece rotate in a direction opposite to the direction of rotation of the grinding element 58, but this is not absolutely essential. Upon the completion of each arc movement of the oscillating plate 33 and associated mechanism, the mechanism already described causes rotation of the nut element 61, with consequent further movement of the grinding means toward the surface of the work piece 20. A usual total of 40 or 50 arcs of grinding movement is sufiicient to provide an entirely spherical true finished surface. The fineness of finish is determined by the grit size of the grinding element. Frequently, a supplemental polishing operation is provided,

using hand application of a polishing paper against the rotating work piece, with the grinding element detached. This avoids the necessity of changing the grinding element to a finer grit stone. Alternatively, if desired, of course, an initial grinding can be followed with a corresponding finishing operation with a finishing abrasive wheel mounted in the apparatus. While best results are obtained using a rotating, circular, grinding wheel, non-rotating grinding elements can be substituted and good results will be obtained.

It will be apparent that numerous variations in the means described for the movement of the grinding means for successive cuts can be provided and similar functioning will be attained. Similarly, the locking means actuated by the air cylinder 81 can be omitted, but this assures substantially absolute radial uniformity of the successive cuts or grinding passes on the work piece.

What is claimed is:

1. An apparatus for surface grinding generally spherical elements comprising, in combination,

(a) means for rotatably supporting a generally spherical element on an axis through substantially the center of said generally spherical element,

(b) means for rotating the rotatably supported generally spherical element on said axis,

(c) rotating grinding means for rotatably grinding the surface of said generally spherical element,

((1) pivotally mova'ble mounting means for supporting the rotating grinding means on a pivotable axis passing through substantially the center of said generally spherical element when the pivotable axis is extended,

(e) means for oscillating the pivotably movable mounting means in an arcuate path,

(f) adjusting means on the pivotably movable mounting means for changing the distance between the rotating grinding means and the pivotable axis of said pivotably movable mounting means,

said means for rotating the rotatably supported generally spherical element comprising a motor driven gear reducer and said means for oscillating the rotating grinding means comprising a speed reducer actuated by said gear reducer and operably connected to said means for oscillating the rotating grinding means by eccentric arm means.

2. The apparatus of claim 1 in which the generally spherical element is the ball of a ball-valve, the means for rotatably supporting said element is engaging means for clamping the ball at its flat faces and centering the ball with respect to the pivotably movable mounting means to cause the grinding means to accurately grind the spherical portion of the balls surface.

References Cited by the Examiner J. A. MATHEWS, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,300,905 January 31, 1967 Henry H. Gardner It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 2, line 28, for "granding" read grinding column 4, line 55, for "338,320" read 338,302

Signed and sealed this 17th day of October 1967.

(SEAL) Attest:

EDWARD J. BRENNER Edward M. Fletcher, 11'.

Commissioner of Patents At t'esting Officer 

1. AN APPARATUS FOR SURFACE GRINDING GENERALLY SPHERICAL ELEMENTS COMPRISING, IN COMBINATION, (A) MEANS FOR ROTATABLY SUPPORTING A GENERALLY SPHERICAL ELEMENT ON AN AXIS THROUGH SUBSTANTIALLY THE CENTER OF SAID GENERALLY SPHERICAL ELEMENT, (B) MEANS FOR ROTATING THE ROTATABLY SUPPORTED GENERALLY SPHERICAL ELEMENT ON SAID AXIS, (C) ROTATING GRINDING MEANS FOR ROTATABLY GRINDING THE SURFACE OF SAID GENERALLY SPHERICAL ELEMENT, (D) PIVOTALLY MOVABLE MOUNTING MEANS FOR SUPPORTING THE ROTATING GRINDING MEANS ON A PIVOTABLE AXIS PASSING THROUGH SUBSTANTIALLY THE CENTER OF SAID GENERALLY SPHERICAL ELEMENT WHEN THE PIVOTABLE MOVABLE MOUNT(E) MEANS FOR OSCILLATING THE PIVOTABLY MOVABLE MOUNTING MEANS IN AN ARCUATE PATH, (F) ADJUSTING MEANS ON THE PIVOTABLY MOVABLE MOUNTING MEANS FOR CHANGING THE DISTANCE BETWEEN THE ROTATING GRINDING MEANS AND THE PIVOTABLE AXIS OF SAID PIVOTABLY MOVABLE MOUNTING MEANS, SAID MEANS FOR ROTATING THE ROTATABLY SUPPORTED GENERALLY SPHERICAL ELEMENT COMPRISING A MOTOR DRIVEN GEAR REDUCER AND SAID MEANS FOR OSCILLATING THE ROTATING GRINDING MEANS COMPRISING A SPEED REDUCER ACTUATED BY SAID GEAR REDUCER AND OPERABLY CONNECTED TO SAID MEANS FOR OSCILLATING THE ROTATING GRINDING MEANS BY ECCENTRIC ARM MEANS. 